Coding apparatus



Jan. 16, 1962 .1. J. SAYKAY 3,017,459

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Jan. 16, 1962 J. J. SAYKAY 3,017,459

CODING APPARATUS Filed July 14. 1958 6 Sheets-Sheet 6 CR- LF LET 2INVENTOR. JOSEPH J. SAYKAY his ATTORNEYS.

3,017,459 Patented Jan. 16, 1962 3,017,459 t CODIN G APPARATUS Joseph J.Saylray, Seacliff, NY., assignor to Fairchild Camera and InstrumentCorporation, Syosset, N.Y., a corporation of Delaware A Filed July 14,1953, Ser. No. 748,341

14 Claims. (Cl. 178-17) This invention relates to coding apparatus, andhas particular reference to such apparatus useful with key operatedwriting mechanisms to store written information in coded form on adesired storage medium.

Key operated mechanisms, such as typewriters, adding machines and likeapparatus, generally provide printed information. In many instances, itis desirable to convert this information into coded symbols on aparticular storage medium, for example, punched tape. Substantialsavings in time may be effected if such coded information is transferredto tape simultaneously with printing by the key operated machine. Forexample, socalled common language machines operating on a veunit orBaudot code are widely used. If printed information can be placed onpunch tape in accordance with that code, it may then be transmittedimmediately or at a later time over telegraph lines or the like, and beread at the receiving end by conventional Teletype printers.

Common language machines utilize the five-unit code which makesavailable only thirty-two different code combinations. Accordingly, twoshift conditions ordinarily designated figures and letters are requiredto increase the possible code combinations to sixty-four. For thatreason, each key of a telegraph printer keyboard carries two characters,one representing the lower case characters or letters and the otherrepresenting the upper case characters or figur-es. In order to receivethe lower case characters correctly, they must be preceded by theletters code symbol and in like manner the upper case characters must bepreceded by the figures code symbol. While the two code symbols arepurely functional in that the letters or figures symbols or codecombinations are not printed, they still must be punched into the tapein order to operate the reading printer correctly.

Greater use of storage mediums such as perforated tape and magnetic tapeis contemplated, and has actually been initiated in fields other thancommunications to provide information storage for data processing,computers and like devices. Therefore, it is desirable in many instancesto use key mechanisms other than telegraph printers, land to modifytypewriters, adding machines, computers and the like to condition themfor use in storing information on punched tape and other mediums.

However, when such modified standard office equipment is used to preparetape punched with the five-unit code, diiculties are encountered becausesuch machines include keyboards consisting of a row or rows of keys inwhich characters are carried in the lower and upper case, as in thestandard typewriter. Such a type-writer keyboard contains four rows ofkeys in which the first row represents the digits 2 to 0 in the lowercase and punctuation marks in the upper case. Thus, the operator is notrequired to depress the typewriter shift key when writing the digits 2to 0. However, if five-unit code tape is being prepared, unless suchdigits are preceded by the figures code symbol, the tape will not beproperly perforated and will actuate the printing mechanism incorrectly.

In this circumstances, it has been necessary to allocate two of thetypewriter keys to provide the figures and letters code symbols on theperforated tape. Obviously, the use of these additional keys will,especially with an inexperienced operator, make for inefficiency in theentire typing operation.

Suggestions have been made that the foregoing problems be overcome byemploying a six-unit code which has enough combinations to representevery key in the typewriter by a distinctly different code symbol. Whileinformation punched in a six-unit code can be transmitted over telegraphlines with the same facility as that in five-unit code, it is, ofcourse, less economical in the use of line time. Thus, for every tenwords in the six-unit code transmitted, eleven and one-half words may betransmitted in the tive-unit code over the same period of time and atthe same cost.

In my copending application Serial No. 504,065, tiled April 26, 1955,apparatus to punch tape with five-unit code symbols for use with keyoperated mechanisms such as typewriters has been described. A diodematrix used in such apparatus was divided into three subassembliesrepresenting letters figures in the lower case and figures in the uppercase. Such a composite matrix results in assembly complexities, a largenumber of separate output terminals and unnecessary size, an importantconsideration because such matr1x must be affixed directly to the keyoperated mechanism involved.

Furthermore, the automatic insertion of the figures and letters symbolsin copending application Serial No. 504,065 required the performance oftwo distinct operations within the time interval extending from thedepression of o-ne printing key to the depression of the next key. Whentwo punchings (letters code and particular letter, for example) withinthe described single interval were required, correct operation of theperforator depended upon the correct timing of selector relays involved.Because of the nature of the five-unit code, load requirements were notuniform and the same relay could become involved in several differenttiming cycles depending on the number of other relays in the particulargroup. As a result certain relays were not releasing quickly enough andsome repetition followed the shift signal. Although that error could beremedied by the proper choice of relays, it does require carefuladjustment in assembly and operation. Y,

My copending application Serial No. 657,886, filed May 8, 1957, of whichthis application is a continuationin-part, relates to coding apparatusutilizing a bipolar diode matrix and circuits to provide two cycles ofoperation the first of which is initiated by depressing a key and thesecond by releasing to key in a key operated mechanism. The presentinvention relates generally to the same type of coding apparatus inwhich the diode matrix has been modified to generate code signals withfewer diodes, and in which the letters and figures code signals aregenerated through the use of means external to the improved diodematrix.

Accordingly, it is an object of the invention to provide an improvedbipolar diode matrix simplified in construction and producing aplurality of coded output signals.

It is a further object of the invention to provide a bipolar diodematrix in combination with external switching elements to producesignals representative of the particular code signals generated by thediode matrix.

It is a further object of the invention to provide coding apparatusincorporating the improved bipolar diode matrix.

These and further objects of the invention are accomplished by the useof a dio-de matrix incorporating diode stacks formed by diodes polarizedin one direction and at le ist some of the stacks incorporating diodesypolarizedin the other direction. @ne set of condu-ctors joins a numberof diodes to the matrix input terminals while another set connectsoppositely polarized diodes to the input terminals.

In one embodiment of the improved bipolar diode matrix Vfor use with thefive-unit code, there are a total of twenty-six diode stacks intwenty-six binary code groups, or positions, each of which may representtwo code symbols, thereby providing a total of fifty-two possiblecombinations or code symbols. This will be evident when it is understoodthat every code symbol in a binary code consists of a number of positiveor marking pulses and a number of negative or spacing pulses. Themarking pulses, expressing one code symbol, can be generated by diodespolarized in one direction, and oppositely polarized diodes positionedin some or all of the spacing positions can be used to generate signalsrepresentative or another code symbol. It is apparent, therefore, thatonly half as many code stacks and binary groups or positions arerequired to represent a desired number of code symbols, using theforegoing arrangement.

In Vother words, to distinguish between two code symbols, the diodes inone stack are oppositely polarized for each code symbol. Thus, if fivediodes are inserted in a stack, and the first and second diodes areconnected to a single input lead, application of a suitable potential tothe lead will provide signals on two output conductors only. If theremaining three diodes are polarized oppositely to the first two diodesand joined to another input lead, which is energized by a potential ofopposite polarity, output conductors three, four and five will carrysignals representative of another `code symbol. In this example, thesecond code symbol is the complement of the first. The second codesymbol may also use only one or two out of the three remaining positionsand not be a true complement. In any event, it is apparent that twodifferent code signals may be provided from a single stack or positionby the use of energizing potentials of different polarities.

In the particular embodiment of the invention described hereinafter (atwenty-six position diode matrix) coded signals indicative of twenty-sixletters may be generated by impressing a potential of one polarity onthe appropriate input leads and coded signals representative of anyselected number of figures up to twenty-six may be represented byimpressing a potential of the opposite polarity on the other inputleads. The reversal of polarity to provide coded output signals from thediode matrix also produces signals representative of figures and letterscode symbols.

One use of the inventive bipolar diode matrix involves the transfer ofinformation printed by typewriters to another storage medium such aspunched tape simultaneously with such printing. To accomplish thatresult, a number of selector relays, five in the case of the five-unitcode, are selectively energized by signals from a diode matrixassociated with the key operated mechanism. Those relays determine,through further circuits, the information transfer devices that must beactuated to punch appropriate code symbols into the tape or suitablyimpress such symbols on any storage medium. Signals from switchingelements associated with the diode matrix also control further circuitsso that when switching from letters to gures or from figures to letters,signals representative of the appropriate code symbol are generated andalso supplied to the information transfer means to punch the tapeappropriately.

In a preferred embodiment of the invention, depressing a key initiatesone cycle of operation in which code symbols such as figures or lettersinformation is punched into the tape, for example. Upon release o-f thekey, a second cycle is initiated in which the character represented bythe key is punched into the tape.

Actuation of another key, such as a typewriter shift key, to conditionthe printing machine for operation of a dual function key, results in achange in polarity of the potential applied to the diode matrix.Accordingly, diodes polarized oppositely to those normally used are theneffective to supply different coded signals to the selector relays.

These and further objects and advantages of the invention will be morereadily understood when the following description is read in connectionwith the accompanying drawings, in which:

FIGURES 1A and 1B show portions of a schematic circuit diagramincorporating an improved bipolar matrix and other apparatus inaccordance with the prin ciples of the present invention;

FIGURE 2 is the remainder of the schematic circuit diagram of FIGURES lAand 1B incorporating the improved diode matrixand illustrating controlelements cooperating with the matrix;

FIGURE 2A shows a stepping switch arrangement that may be substitutedfor a polar relay in FIGURE 2;

FIGURE 3 is a view in perspective of one end of the diode matrix ofFIGURE l together with switching elements cooperating to provide codesignals representative of figures and letters;

FIGURES 4, 5 and 6 are plan views of switch contact strips illustratedin FIGURE 3;

FIGURE 7 is a fragmentary view in perspective of one end of a printedcircuit that may be incorporated in the circuits o-f FIGURES 1A and 1B;

FIGURE 8 illustrates a piece of tape perforated by the apparatus ofFIGURES lA, lB and 2; and

FIGURES 9A and 9B comprise a timing chart helpful in understanding theoperation of disclosed embodiment of the invention in perforating thetape of FIGURE 8.

Referring to an illustrative embodiment of the invention in greaterdetail with particular reference to the drawings, apparatus adapted tobe employed with a standard keyboard typewriter is sho-wn. It will beunderstood, however, that the invention is n-ot limited to typewriterslbut may utilized with adding machines, computers, and like mechanisms.Moreover, the inventive apparatus may also be used in code inverters.

The improved bipolar matrix of FIGURES 1A and 1B comprises twenty-sixdiode or code stacks 1.0 in a like number of code positions formed by aselected number of unidirectional conducting elements or diodes 11polarized in one direction and similar diodes I2 polarized in theopposite direction. Negative potentials on input conductors 13 arecoupled selectively by the diodes 1I to five output conductors 14 to IS,inclusive, lfastened to diagrammatically represented output terminals 1to 5, since the five-unit or Baudot code is being used in the examplegiven. Positive potentials on other input conductors 19 are coupledselectively by the diodes 12 to the same output conductors I4 to 18.

Input terminals 2d of the diode matrix are connected to one or more ofthe input conductors 13 and I9 by conductors formed in a printed circuit21, shown in detail in FIGURE 7. Vertical conductors 22, leading fromthe input terminals 20, may be formed by copper strips deposited on oneside of a phenolic plate '23. Similarly formed horizontal conductors 24on the other side of the plate 23 are selectively connected to thestrips 2.2 by conthree conductive strips or combs 27, 28 and 29 formedVwith lateral spring contact lingers 3i), 31 and 32, respectively. Thecontact fingers 32 are associated with a first group of input terminals20, in this case the terminals representative of lettersf and thecontact fingers 31 with a second group representative of figures Thestrips or combs are secured to opposite sides of insulating strips 33and 34 with one contact finger 30 above each terminal 2i) and selectedones of the fingers 3l and 32 positioned between each resilient finger30 and correspending figure or letter" terminals Zti, respectively.

To applyy potential to the diode matrix, bell crank cams 35, rotatablymounted on an insulated fixed shaft 36 are joined by suitable operatingsprings 37 to any desired element on a typewriter with which the diodematrix is associated, the springs being urged in the direction of thearrow when a corresponding typewriter key is depressed. Initial movementof the bell crank 35 displaces its associated spring finger 3ft intoengagement with one of the fingers 3l and 32, and further movement ofthe crank cams both fingers against the terminal 2li.

A conductor 3S, connected in a manner described hereinafter, energizesthe strip 2'7 and fingers 3) so that depression of a particulartypewriter key (not shown) carrying one of the characters indicated inFIGURES 1A and 1B causes an associated one of the bell cranks 35 to camone of the fingers liti against one of the fingers 31' or 32 initially,thereby energizing one of the strips 28 or 29 and supplying a signal onone of output conductors 39 or 40, respectively connected thereto (FIG-URES 4 to 6).

Signals on the lines 39 and d@ are respectively coupled through windingsdla and aib (FIGURE 2) of a twowinding relay 42, controlling an`armature 43, to magnets 44 and 45 of a polar relay do, the return beingthrough a conductor 47. The magnets 4d and l5 in the relay i6 actuate anarmature d3 between a pair of contacts connected in a manner describedhereinafter. To control the output signals from the diode matrix inaccordance with the condition (shifted or unshifted) of the associatedtypewriter, a relay de) operates in accordance with depression of atypewriter shift key Sti to change the polarity of the potential on theconductor 33 which, in turn, reverses the polarity of the voltageapplied to the diode matrix terminals 2@ through the spring fingers 341.

More specifically7 normally negative and positive potentials aresupplied to the back contacts of armatures 51 and 52, respectively, ofthe relay d2?. Displacement of the armatures 5l and 52, the formerengaging its front contact which leads to a conductor 53 normallycarrying a positive potential, and the latter being energized by anegative potential on a conductor 5d, results in a reversal ofpolarities on the conductors 38 and 59. The diode matrix thereby issuppled through the spring fingers 30, 31 and 32 with negative orpositive potentials, acoording to the position of the typewriter shiftkey 50.

The output conductors le to i8 normally couple signals from the diodematrix through armatures 5S of a relay 56 (FIGURE 2) to selector relays57 to actuate them in accordance with the code combination associatedwith the particular character on a selected typewriter key. One side ofeach of the relays 57 is normally supplied with a positive potentialthrough conductors 5S and 59 which lead to the armature 52 of the relay49 (FIG- URE l).

Each of the relays 57 is provided with a hold circuit armature ditcoupled through a conductor 6i, the armature d3 of the relay d2, whenactuated, and yanother oonductor 62 to the line 3S. Accordingly, uponenergization of any one of the relays 57, the armature 69 engages itsfront contact which leads to one side of the energized relay. Theresulting hold circuit for that particular relay remains intact as longas the relay 42 is excited, this inn terval being determined by thedepression time of any one of the typewriterv keys.

A second armature 63, maintained at a negative potential by a line 64,is also actuated by each of the relays 57 to energize, through aconductor 65, the relay S6 whose other side is returned to a positivepotential. It will be apparent that when the relay 56 picks up, thediode matrix will be disconnected from the selector relays 57 by thearmatures 55. As pointed out in the above-referred to copendingapplications, such disconnection eliminates the adverse effects ofcurrent leakage through the diodes and prevents unwanted operation ofany ofthe selector relays 57.

A further armature 66, when actuated by the relay 56', completes acharging circuit through a resistor 67 to a capacitor 68, the resistor67 being joined to a negative potential and the relay forward contactbeing energized by a positive potential. Accordingly, upondeenergization of the relay 56, the armature 66 engages its back contactand the capacitor 58 discharges through conductors 69 and 7@ to operatea punch solenoid 71 of conventional designt returned to a negativepotential.

Each relay 57 controls a third armature 72 connected through a capacitor73 and a resistor 74 to a source of positive potential. When actuatedagainst their forward contacts, each capacitor 73 is charged from anegative potential through a conductor 75. Accordingly, the capacitor 73discharges, when the relay 57 releases, through a conductor 76 to amagnet coil 77 in a perforator 7, one coil 77 being provided for each ofthe selector relays S7. The other side of each coil 77 is returned to apositive potential through a conductor 79.

The perforating mechanism including the magnet coils 77 and punch 71have not been described in detail since any conventional apparatus wellknown in the art may be used to perform their functions. It suffices tosay that when the punch 7l operates, it perforates the tape and steps itforward, the perforations being in accordance with the perforator magnetcoils 77 that are or have been energized. Moreover, operation of thepunch solenoid 71 resets the perforator 7S.

Since the tive-unit or Baudot code affords only thirtytwo differentsignal combinations, it is necessary to use the same code combinationstwice and to identify them as figures or letters combinations by anappropriate code symbol on the punched tape, or other storage mediumsuch as magnetic tape, preceding the coded information. In the past, apair of additional keys on a typewriter converted to this use wererequired so that the operator could place the figures or letters codeinformation on the tape and this, of course, considerably slowed thetyping operation. in the present instance the polar relay 46, whichactuates the armature d between a pair of contacts, provides, togetherwith additional apparatus described hereinafter, automatic punching ofthe figures and letters code on the perforated tape.

More particularly, the figures conductor 39 when energized excites themagnet 4d to displace the armature 48 against a contact joined to aconductor Si) leading to a relay 8l which is returned to a negativepotential. When energized, the relay di actuates an armature 82 againstits front contact. A previously charged capacitor 83 discharges througha resistor Sd, a conductor 8S and a further relay 85, returned to anegative potential, to operate the relay 36 momentarily. Such operationdisplaces four negatively biased armatures 87 against front contactsleading through conductors Sii to four of the perforator coils 77. Afurther armature 89 discharges a charged capacitor 90, when actuated,through conductors 9i, 92 and 70 to operate the punch solenoid 7i.Accordingly, the figures code symbol is punched into the tape.

When the letters conductor it? is energized, the magnet 45 actuates thepolar relay armature 4S against its other contact to energize aconductor 93 and operate a relay 94 which picks up three armatures $5,95 and 97. A charged capacitor 93, connected to the armature 95, isdischarged through a conductor 99 and a relay itl@ to operate fivenegatively biased armatures itil momentarily. This energizes theconductors 8S leading to all five of the perforator magnet coils 77,thereby conditioning the punching mechanism to punch the letters codesymbol on the tape. A further armature 102, joined to the chargedcapacitor 99, energizes, when actuated, the punch solenoid 71 throughthe conductors 91, 92 and 70 to punch the letters symbol into the tape.

, A stepping switch arrangement, such as shown in FIG- URE 2A, mayreplace the polar relay 46. The switch incorporates two sets of contacts46a and 46h. The first Set 46a includes alternate contacts connected tothe conductors 44a and 45a, respectively, and the second set 46hincorporates alternate contacts joined to the conductors 80 and 93,respectively. A rotating arm 46c is connected by a sliding contact 46dto one side of a stepping magnet 46e, its other side being energized bythe conductor 47. The arm 46c is ganged with a similar arm 46j inthecon- Ifact set 4611. A sliding Contact 46g, connected to a positivepotential, energizes the arm 46]", whereby stepping of the arm `46falternately energizes the conductors 30 and 93.

With the arms 46c and 46j positioned as shown in FIGURE 2A, energizationof the figures control conductor 39 and the conductor 44a will notaifect the stepping switch. Energization of the letters controlconductor 40 and the conductor 45a will, however, cause the switch toadvance one step, thereby energizing the conductor 93 and deenergizingthe conductor S0.

Returning to the relay 94, the armatures 96 and 97 when operated reversethe polarity of the conductors 53 and 54, leading to the front contactsof the relay 49 (FIGURE l), for a purpose apparent from the hereinlafterdiscussion of the operation of the present system.

A tape feed key switch 56a also may be depressed to energize the relayS6 thereby charging the capacitor 63. Release of the armature 66energizes the punch solenoid 71 to step the tape without perforatingsince none of the coils 77 have been energized. If it is desirable toprovide for rapid automatic tape feed, a vibrating relay may beincorporated to energize and deenergize the relay 56 repeatedly whilethe switch 56a is depressed.

A carriage return-line feed key switch 103 when depressed closes acircuit to a relay 104.l which picks up armatures 105 to 108. Thenegatively bised armature 105 energizes one of the perforating coils 77through one of the conductors 88. At the same time, actuation of thearmature 106 discharges a capacitor 109, previously charged through aresistor 110, through conductors 111, 92 and 70 to operate the solenoid'71 and punch the carriage return code symbol on the tape. Upon releaseof the key 103, the armature 107, which in its actuated positionprovides a charging circuit for a capacitor 112, engages its backcontact and energizes one of the perforating magnet coils '77 throughconductors 113 and 88. Simultaneously, the armature S, which functionsto charge a capacitor 114 when actuated, returns to its back contact andthrough conductors 115, 92 and 70 energizes momentarily the solenoid 71to punch the line feed code symbol.

Several typical operating cycles of the above-described illustrativeembodiment of the invention will now be described with particularreference to the perforated tape of FIGURE 8 and the timing chart ofFIGURES 9A and 9B. In the interests of clarity, each of the relays isidentitied by a letter and number such as R1, R2, R3, etc., as well asby a reference numeral.

Assuming first the depression of the typewriter key Q, the bell crank 35cams the spring fingers 30 and 32 together and against the terminal toenergize the strip 29 and the terminal 20 of the stack 10. The resultingsignals from the diode matrix actuate the selector relays 57 (R1, R2, R3and RS), such signals being supplied by ythe diodes 11 and the signaloutput conductors 14, 15, 16 and 18, respectively. in addition, theletters line 40 is energized by the strip 28 and causes the relay 42(R20) to pick up its armature 43 and close a hold circuit for theselected relays 57.

The magnet 44 in the polar relay 46 (R12) also responds to signals onthe line 40 to shift its armature 4S to the letters position if afigures key had been operated Y previously. The relay 94 (R15) thenpicks up its armature 95 to energize the relay 100 (16) momentarily sothat the armatures 101 are shifted to energize the'relay coils 77 (R6 toR10) in the perforator 78. At the same time, the armature 89 initiatesoperation of the punch solenoid 71 (R19) to punch the letters codesymbol on the tape, as shown in FlGURE 8.

The timing chart of FIGURE 9A illustrates clearly the foregoingsequence, the fast-acting polar relay R12 closing its Contact shortlybefore the relays R1, R2, R3 and R5 pick up their armatures. As soon asone of the armatures 63 engages its front contact, the relay 56 (R11) isenergized to disconnect the selector relays 57 from the diode matrix andinitiate charging of the capacitor 68. Moreover, the hold relay (R20)maintains the relays 57 operated for as long as the key Q is depressed.

Upon release of the typewriter key Q, the relay 42 drops out to open thehold circuits for the relays 57. As a result, those relays aredeenergized and their armatures 72 engage back contacts and energize theperforator selector magnets 77 (R6, R7, R3 and R10). In addition, thearmature 63 open the energizing circuit for the relay 56 to permit thearmature 66 to swing against its back contact. That action dischargesthe capacitor 68 through the solenoid 71 to punch the Q code combinationon the tap-e, as will be evident from the tape of FIGURE 8` and thetiming chart of FiGURES 9A and 9B.

1t will be apparent from the above that depressing the key Q results inone series of operations and releasing the key ano-ther. In other words,two separate operating cycles of the relays in the inventive apparatusoccur the first during depression `and the second during release of atypewriter key, and this contributes greatly to the eiciency andreliability of the system.

lf the letter A must next be printed by the typewriter and punched onthe tape, depression of the appropriate key results in the actuation ofthe bell crank 35 and the energization of the selector relays 57 (R1,R2). 1n this instance, however, the polar relay armature 48 remains Iinits letters position and the letters code symbol is not punched on thetape. Upon release of the typewriter key A the relay 42 (R20) drops outcausing the appropriate code symbol to be punched in the tape by thesolenoid 71 (R19).

In operating the typewriter, the shift key 50 Will be depressed to printcapital letters. Assuming that this operation occurs when the letter Alis to be printed, the relay 94 (R15) remains energized through the polarrelay armature `4S so that the armatures 96 and 97 supply negative andpositive potentials, respectively, through the conductors 53 and 54 tothe front contacts engaged by the armatures 51 and 52 of the relay 49(R18). Accordingly, energization of the relay 49 by the shift key 50fails to change the polarity on the lines 38 or 59 while capital lettersare being printed.

1f the figure 2 is to be printed, actuation of the appropriate bellcrank 35 results in the excitation of suitable relays 57 (R1, R2, andR5). Moreover, due to energization of the correspond-ing resilientfinger 31 and the strip 28, a signal is coupled through the figures line39 to energize the relay 42 (R20) and the magnet 44 of the polar relay46 (R12).

The polar relay armature 4S snaps against its figures contact to pick upthe relay 81 (R13) and actuate the armature 82 against its forwardcontact, thereby discharging the capacitor 03 through the relay 86(R14). Accordingly, the armatures 87 engage their front contacts toenergize the pcrforator relay magnets 77 (R6, R7, R9, and R10). At thesame time, the armature 89 engages its front Contact and the capacitori90 discharges through the punch solenoid 71 (R19) to punch the figurescode on the tape. Upon release of the typewriter key 2, the relay 42drops out and the figure 2 is punched in the tape in the mannerdescribed above in connection with the letter Q. f

Assuming that a quotation mark is to be printed, the typewriter shiftkey 50 is depressed and the resulting energization of the relay 49 (R18)actuates the armatures 51 and 52 against their front contacts which leadthrough the conductors 53 and 54 and the armatures 96 and 97 to positiveand negative potentials, respectively. Accordingly, the potentials onthe lines 38 and 59 are reversed. Subsequent depression of the quotationmark key operates the corresponding bell crank 35 to urge the springfingers 30 and 31 together and against the terminal 2t), and a positivepotential is applied through the strip 27, the lingers 30 and 31, theterminal 20 and the corresponding conductor 19 to the diodes 12 in thecorresponding stack 10.

It will be apparent from FIGURES lA and 1B that the diodes 12, polarizedoppositely to the diodes 11, will be effective to energize the lines 14and 18 and the selector relays 57 (R1 and R5), which are returned to theline 59, now of negative polarity. The figures line 39 is also energizedwhen the linger 3() engages the linger 31 and completes a circuit fromthe positive line 3% through the strip 27, the lingers 3@ and 31, thestrip 28, the line 39, the winding 41a, the magnet 44 of the polar relay4o, and the line 47 to the now negative line 59. Since the polar relayarmature 4S remains in the figures position, the figures symbol will notbe punched on th-e tape. The quotation mark symb-ol will, however, bepunched in the usual manner upon release of the typewriter key, whichopens the circuit to the relay 42 and causes a perforating operation.

The remaining operations-to punch the tape illustrated in FIGURE 8 willbe apparent from the time charts of FIGURES 8a and 8b. However, it mightbe well to examine the carriage return-line feed operation which isinitiated by depressing the switch key 1113. The relay 104 (R17) picksup its armature 105, which energizes the perforator magnet relay 77(R9), and its armature 106, which operates the punch solenoid 71 (R19).Accordingly, the carriage return symbol is punched in the tape. Thearmatures 1117 and 103 are also picked up at this time to charge thecapacitors 1119 and 112. Upon release of the key 163, the armatures 107and 108 are returned to their back contacts to energize the perforatormagnet 77 (R7) and the solenoid 71 (R19) to punch the appropriate linefeed code symbol in the tape.

Considering` next the functioning of the apparatus, if the ligure "4 isto be printed,- actuation of the appropriate bell crank 35 results intheexcitation of the relays S7 (R2 and R4). Moreover, due to theenergization of the appropriate resilient linger 31 in the strip 38, asignal is coupled through the figures line 39 to energize the relay 42(R20) and the magnet 44 of the polar relay 46 (R12).

The polar relay armature 48 snaps against its figures contact to pick upthe relay 81 (R13) and actuate the armature 82 against its forwardcont-act, thereby discharging the capacitor 83 through the relay 86(R14). Accordingly, the armatures 87 engage their front contacts toenergize the perforator relay magnets 77 (R6, R7, R9, and R10). At thesame time, the armature 89 engages its front contact and the capacitor90 discharges through the punch solenoid 71 (R19) to punch the gurescode on the tape. Upon release of the typewriter key 4, the relay 42drops out and the ligure 4 is punched in the tape in the mannerdescribed above in connection with the letter Q.

When cross connections are made by one of the conductors 24 so thatdepressing typewriter keys to print the letter R or the ligure 4energizes, through one of the conductor-s 13, thev same code stack 10,there will be no difiiculty. On the :other hand, if the shift key 50 isoperated to print the dollar sign which is located on the same key asthe number 4, the letter R conductor 22' must be connected by anotherone of the con ductors 24 to a code stack which, in reverse, generatesthe code combination representative of the letter D', which alsorepresents the dollar sign (it).

Referring to FIGURES lA and 1B, in the code stack 10 at position 17 thediodes 12 are positioned to energize the conductors 14 and 17 whenpositive potential is supplied to the diode matrix. Normally, the codesymbol for the letter H is generated by the diodes 11 in position 17when negative potential is applied to the diode matrix. With theforegoing arrangement, operation of the key representative of the letterH will not cause false printing of the letter R.

In the illustrative embodiment of the invention described herein, onegroup of input terminals associated with keys representative of singlecharacters are joined by conductive means includring conductors 13, 22and 24 to the diodes 11 in the stacks 10, while a second group of inputterminals associated with keys representative of two characters arejoined by conductive means including conductors 19, 22 and 24 to thediodes 12 in the stacks 10. t is necessary, as is apparent from FIGURESlA and 1B, to provide ten separate positive paths to the diodes 12 atcode positions 2, 3, 4, 5, 9, 13, 17, 18, 22 and 25.

It will be evident from the foregoing that by using complementarycombinations of the diodes 11V and 12 in selected code stacks, a greatnumber of diodes may be eliminated by use of the improved bipolarmatrix. For example, the code symbol for the letter A in the live-unitcode is l and 2 having a complement of 3, 4 and 5 which, in that code,represents a period Referring to FIGURES 1A and 1B, the typewriter keyrepresenting a period when depressed closes a circuit to one of theconductors 19 leading to the diodes 12 in the code stack 11B in position2, also representative of the letter A. Simultaneously the figures`conductor 39 will be energized through the corresponding contact linger31 and strip 28 to shift the pola-r relay 46, if necessary, and changethe polarity on the line 3S to energize the lines 16, 17 and 1S and theselector relays 57 (R3, R4 and R5) through the oppositely polarizeddiodes 12. Punching of the tape then is accomplished as above.

From the above, it will be apparent that the present apparatus may beemployed to convert standard key operated mechanisms such as typewritersto machines capable `of perforating tape with a live-unit code. Byvirtue of the automatic punching of the letters and figures codesymbols, the two additional keys necessary in prior devices of this typeto perform those functions may be eliminated to incr-ease the eliiciencyof the typing operations. Moreover, the improved diode matrix minimizesthe number of necessary diodes.

It will be understood that the above-described embodiments of theinvention are illustrativey only and modifications thereof will occur tothose skilled in the art. Therefore, the invention is not to be limitedto the specific apparatus disclosed herein but is to be defined by theappended claims.

I claim:

l. ln coding apparatus, a diode matrix comprising: a plurality of inputterminals; a plurality of output conductors; a plurality of diode stackseach including a plurality of groups of one or more diodes each; meansincluding a code selector for connecting the diodes of eachcorresponding group of each of said stacks to a different one of saidinput terminals; and circuits for connecting all of said diodes of eachstack to different output conductors.

2. lIn coding apparatus, a diode matrix comprising: a pair of inputterminals of opposite polarlties; a plurality of output conductors; aplurality of diode stacks each including two groups of one or morediodes each; means including a code selector for connecting the diodesof one corresponding group of each of said stacks to one of said inputterminals with one polarity and for connecting the diodes of the othercorresponding group of each of said stacks to the other input terminalwith opposite polarity;

'M and circuits for connecting all of said diodes of each stack todifferent output conductors.

3. In coding apparatus, a diode matrix comprising: x input terminals; aplurality of output conductors; a plurality of diode stacks eachincluding x groups of one or more diodes each; means including a codeselector for connecting the diodes of each corresponding group of eachof said stacks to a different one of said input terminals; and circuitsfor connecting all of said diodes of each stack to different outputconductors whereby a total of x25' possible code combinations may begenerated.

4. In coding apparatus, a diode matrix including input terminals infirst and second groups, output conductors, a plurality of diode stacksconnected in parallel across the output conductors, first conductivemeans joining each of the diode stacks to one of the first group inputterminals, second conductive means joining selected ones of the diodestacks to one of the second group input terminals, an input conductor,switching means operable to connect the input conductor to each of theinput terminals, a first control conductor connected by the switchingmeans to the input conductor when the input conductor is connected toone of the first group input terminals, and a second control conductorconnected by the switching means to the input conductor when the inputconductor is connected to one of the second group input terminals.

5. Apparatus as defined in claim 4, wherein said switching meanscomprises two conductive members each incorporating a plurality ofcontact fingers and respectively connected to the first and secondcontrol conductors, each of the fingers of one of the conductive membersbeing positioned adjacent to a corresponding one of the first groupinput terminals, each of the fingers of the other of the conductivemembers being positioned adjacent to the second group input terminals, adisplaceable element connected to the input conductor and associatedwith each of the input terminals, displacement of the elementelectrically connecting it to the corresponding contact finger and inputterminal, whereby the input conductor is connected to one of the rst andsecond control conductors.`

6. In coding apparatus, a diode matrix having a plurality of inputterminals, two conductive members each incorporating a plurality ofcontact fingers, each of said contact fingers being positioned adjacentto a corresponding one of the input terminals, and a displaceableelement associated with each of the input terminals, displacement ofsaid element electrically connecting it to the corresponding contactfinger and input terminal.

7. In coding apparatus, a diode matrix having a plurality of inputterminals, three conductive members respectively incorporating first,second and third contact fingers, one of the first contact fingers beingpositioned adjacent to each input terminal, the second contact fingersbeing positioned between the first fingers and some of the inputterminals, the third contact fingers being positioned between the firstfingers and others of the input terminals, a cam associated with eachfirst contact finger to displace it toward the corresponding inputterminal, whereby displacement of each of the first contact fingers byits associated cam electrically connects the first member, one of thesecond and third members, and one of the input terminals.

8. In coding apparatus, a diode matrix having a plurality of inputterminals, two conductive members each incorporating a plurality ofcontact fingers, each of the fingers being positioned adjacent to acorresponding input terminal, a movable element associated with each ofthe input terminals and positioned adjacent to a corresponding one ofthe contact fingers, initial displacement of each of said elementselectrically connecting it to the corresponding contact nger, andfurther displacement of the element electrically connecting the fingerand element to the corresponding input terminal.

9. In coding apparatus, a diode matrix having a plurality of inputterminals and output terminals, three conductive members eachrespectively incorporating a plurality of first, second and thirdresilient contact fingers, each of said first fingers being positionedadjacent to one of the input terminals, said second fingers beingpositioned adjacent to some of the input terminals, said third ngersbeing positioned adjacent to the others of the input terminals, a shaftadjacent to the conductive members, movable cams spaced along the shaftassociated with each of the first resilient lingers, initial movement ofone of the cams connecting the associated rst resilient fingerelectrically to one of the first and second resilient fingers, andfurther movement of the cam electrically connecting the first finger andthe one of the first and second fingers to the associated inputterminal.

l0. lin coding apparatus, a diode matrix including first and seconddiodes, input terminals in first and second groups, a plurality ofoutput conductors, diode stacks connected in parallel across the outputconductors, each of the stacks including at least one diode connected toone of the output conductors, said first and second diodes in any onestack being connected to different output conductors, first conductivemeans joining the first diodes in each stack to at least one of thefirst group of input terminals with one polarity, and second conductivemeans joining the second diodes in each stack to one of the second groupof input terminals with the opposite polarity.

ll. In coding apparatus, a diode matrix including first and seconddiodes, input terminals in first and second groups, a plurality ofoutput conductors, diode stacks connected in parallel across the outputconductors, each of the stacks including at least one diode connected toone of the output conductors, said first and second diodes in any onestack being connected to different output conductors, first conductivemeans joining the first diodes in each stack to at least one of thefirst group of input terminals with one polarity, second conductivemeans joining the second diodes in each stack to one of the second groupof input terminals with the opposite polarity, an input conductor,switching means operable to connect the input conductor to each of theinput terminals, a first control conductor connected by the switchingmeans to the input conductor when the input conductor is connected toone of the first group input terminals, and a second control conductorconnected by the switching means to the input conductor when the inputconductor is connected to one of the second group input terminals.

12. Apparatus as defined in claim l1, wherein said switching meanscomprises two conductive members each incorporating a plurality ofcontact fingers and respectively connected to the first and secondcontrol conductors, each of the fingers of one of the conductive membersbeing positioned adjacent to a corresponding one of the first groupinput terminals, each of the fingers of the other of the conductivemembers being positioned adjacent to the second group input terminals, adisplaceable element connected to the input conductor associated witheach of the input terminals, displacement of each of the elementselectrically connecting it to the corresponding contact finger and inputterminal, whereby the input conductor is connected to one of the firstand second control conductors.

13. In coding apparatus, a diode matrix including first and seconddiodes, a plurality of input terminals, a plurality of diode stacks,output conductors connecting said diode stacks in parallel, at least onefirst diode in selected stacks to generate coded signals on the outputconductors when energized by potentials of one polarity, at least onesecond diode in selected stacks to generate coded signals on the outputconductors when energized by potentials of the opposite polarity, saidfirst and second diodes in any one stack being connected to differentoutput conductors, conductive means connecting said first diodes to oneof said input terminals with one polarity and said second diodes toanother of said input terminals with opposite polarity, two conductivemembers each incorporating a plurality of Contact iingers, each of saidcontact fingers being positioned adjacent to a corresponding one of theinput terminals, and a movable element adapted to be electricallyenerized associated with each of the input terminals, displacement ofsaid movable element electrically connecting it to the correspondingcontact finger and the associated input terminal to provide la. controlsignal on one of the two conductive members and energize the diodematrix which provides coded signals on the output conductors as afunction of the polarity of the energizing potential on said movableelement.

14. In coding apparatus, a diode matrix including first and seconddiodes, input terminals in first and second groups, a plurality ofoutput conductors, diode stacks each including at least one of the twotypes of diodes connected to one of the output conductors to generatecoded signals on the output conductors when energized by suitablepotentials, said irst and second diodes being connected to diierentoutput conductors in any one of the stacks, first conductive meansconnecting the first diodes in each stack to at least one tirst groupinput terminal, second lconductive means connecting the second diodes ineach stack to at least one second group input terminal, two conductivemembers each incorporating a plurality of resilient contact fingers,each of the contact fingers being positioned adjacent to a correspondinginput terminal, a movable element adapted to be electrically energizedassociated with each of the input terminals and positioned adjacent tothe corresponding resilient finger, initial displacement of the movableelement electrically connecting it to the resilient finger to provide acontrol signal on one of the two conductive members, and furthermovement of the cam element electrically connecting it to an associatedinput terminal to energize the diode matrix which provides coded signalsas a function of the polarity ofthe energizing potential on said movableelement.

References Cited in the file of this patent UNTED STATES PATENTS2,244,700 Horton June 10, 1941 2,655,625 Burton Oct. 13, 1953 2,665,336Saykay Jan. 5, 1954 2,673,936 Harris Mar. 30, 1954 2,747,045 Parmer May22, 1956 2,823,368 Avery Feb. 11, 1958 2,907,984 Anderson Oct. 6, 1959

